The present invention relates generally to the field of semiconductor wafer testing, and more particularly, to a non-contact method for testing such wafers.
There are a variety of important measurements that must be made on a semiconductor wafer to determine whether it is suitable for further device processing and to make process adjustments. Examples of such measurements include doping concentration measurements, MOS time retention measurements, and general leakage measurements. However, present measurement techniques have repeatability problems,and those techniques that utilize metal-oxide-semiconductor structures to make the measurements destroy the wafer under test.
The invention as claimed provides a method for facilitating and performing a variety of non-contact measurements on a semiconductor wafer. The claimed method features steps which minimize wafer surface leakage effects.